LEFTB Function in Excel: Leftmost Bytes

LEFTB Function in Excel: Leftmost Bytes 1
⏱ 1 min readUpdated 5 October 2026

TextLevel: ExpertAvailable in: Excel 2007+

In this article
  1. Syntax
  2. Examples
  3. Example 1
  4. LEFTB in practice
  5. Where you will use it
  6. Worked example
  7. Mistakes people make
  8. Related functions

LEFTB returns the first characters based on bytes. In English (single-byte) setups it behaves exactly like LEFT; it differs only when a double-byte language (Japanese, Chinese, Korean) is the default editing language.

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Syntax

=LEFTB(text,3)
Argument What it means
text Text to work on

Examples

Example 1

=LEFTB(A2,3)

Result: Mum. See the worked example table below for more cases.

LEFTB in practice

Where you will use it

  • Japanese, Chinese or Korean data
  • Fixed-width files measured in bytes
  • Cleaning full-width characters from imported forms

Worked example

TextFormulaResult
Mumbai=LEFTB(A2,3)Mum
Excel=LEFTB(A3,3)Exc
12345=LEFTB(A4,3)123

Results calculated in Excel. Calculated on an English (single-byte) Excel.

Mistakes people make

MistakeWhat to do instead
Expecting different results in EnglishIn single-byte setups the B versions match LEFT, LEN, etc.
Mixed-width dataNormalise with ASC first

LEFT · LEN · MID

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